JP3394041B2 - Electric cable - Google Patents

Abstract

The present invention relates to an electric cable which includes at least one cable part and at least one shield which surrounds at least one cable part, and which further includes a plastic or a rubber sheath which embraces the cable part or parts and the shield, wherein each cable part includes a conductor made of copper wire or some other electrically conductive material, and a plastic or a rubber insulating layer. According to the invention, the shield (4) is comprised of one or more prefabricated, woven or braided bands which are placed longitudinally around the cable part or parts (1). The total width of the shield band or bands (4) is roughly equally as large as the perimeter of the underlying construction.

Description

Description: TECHNICAL FIELD The present invention comprises at least one cable section, at least one shield or screen surrounding the at least one section, and a plastic or rubber sheath surrounding the section and the shield. It is related to the electric cable including. Each cable section includes a conductor made of copper wire or other conductive material and an insulating layer of plastic or rubber.

BACKGROUND ART Shielded cables are used in environments where there is a risk of electrical and / or magnetic disturbances. The shield structure and thus the function of the shield will thus depend on the environment from which the cable is to be protected.

The simplest shielded cable is the so-called coaxial cable, which has an insulated conductor or cable section surrounded by a spirally wound wire or a braided shield or screen. The shield is wrapped by a cable sheath. The effectiveness of the shield can be further enhanced by placing a metal foil between the cable portion and the shield and / or between the shield and the cable sheath.

When a cable is shielded by a spirally wound wire, it is difficult to maintain sufficient tightness or compactness of the shield when bending the cable, for example, because the bending of the cable causes the shielded wire to be shielded. Would slip on the outer surface of the cable bend and separate. Thus the shielding function is compromised in this position, which is of course a disadvantage.

The braided shield consists of a number of wires arranged according to a predetermined pattern. Such shields suffer from many manufacturing drawbacks. One of the main drawbacks is the difficulty in achieving serial production because of the need to stop production to make the necessary wire changes. Moreover, braiding is a relatively time consuming process and is therefore usually performed in a separate fabrication step.

Another drawback lies in connecting the braids. If a crimp connection or any similar connection is made, the sleeve is pushed under the braid after stripping the cable. Due to the shape of the braid, this is sometimes difficult to achieve, especially as it is difficult to insert the sleeve into the shield.

Another drawback with braided shields is that the shields are connected to the electrical contacts separately. When stripping the cable, the braided shield is loosened and cut from the cable section and formed into a separate conductor. This job is difficult and time consuming,
There is also a risk that the cable section will be cut and damaged.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of shielding a cable of the type described above, which method leads to improved properties in terms of process, shielding and handling. The new concept provides a new cable that has the same electrical properties as the braided shield, but has more practical effects, especially from a process and handling standpoint. This is achieved by a new cable having the features set out in the appended claims.

According to the invention, the shield consists of one or more pre-made shield bands that are woven. The shield band also has a longitudinally extending (tin plated) copper wire and a lateral retaining wire. The wire extending in the longitudinal direction can be made of a material other than copper.

The shield band is provided in the direction of the longitudinal axis of the cable. The overall width of the shield band is greater than the perimeter of the underlying structure to form the overlap.

When a woven band is used, the band can be formed in various ways. The wires present in the band need not have the same diameter according to the following:

That is, the overlapping wires that extend longitudinally along the side edges of the band can be configured to have a smaller diameter than the remaining wires. This offers the advantage of a smaller diameter in the overlap and a smoother cable. It is also possible for the wires extending in the longitudinal direction to have different diameters in order to obtain a locking effect in said overlap.

The function of the wires in the transverse direction is adjusted as follows.

The shield has an effective shielding ability.

  The band structure is held together.

  The band shield is flexible.

All longitudinally extending shield wires preferably extend in the axial direction of the cable, i.e. parallel to said axis. This ensures that the conduction loss due to the pitch of the shield wire is not incurred. This allows the shield area to be as large as the conductive area if desired.

The present invention will now be described in more detail with respect to its preferred exemplary embodiments as well as the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a cable having a cable portion and a shield surrounding the cable portion, a so-called coaxial cable.

FIG. 2 illustrates the configuration of a shield with an invisible overlap provided on the electric cable of the embodiment of the present invention.

Figures 3a and 3b illustrate alternatives to the novel shield with locking overlap.

  FIG. 4 is a schematic illustration of the structure of the shield band.

FIG. 5 schematically illustrates a shield band formed to provide an electrical connection.

Figures 6 and 7 show alternative shields having different types of cables with several cable sections and provided with a shield formed in accordance with the present invention.

FIG. 8 illustrates in principle how a T-joint is made in a cable constructed according to the invention.

FIG. 9 illustrates one step in the connection of the T-joint according to FIG.

FIG. 10 illustrates the connection of the cable shown in FIG. 9 to one half of the T-joint.

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 shows a cable with only one cable part 1 and a shield 4 surrounding said one cable part,
It is a cross-sectional view of a so-called coaxial cable. The cable may include several cable sections, each or only some of which may be surrounded by a shield, and sections of a multi-part cable each as detailed below. It will be appreciated that it may be surrounded by a further shield of the. Each cable portion 1 is a conductor 2 of copper wire or other electrically conductive material, optionally tinned.
And optionally an insulating layer 3 of a halogen-free plastic or rubber material or a mixture of these materials. Provided on the outside of the cable is a protective holding sheet or jacket 5, which optionally consists of an insulating layer of halogen-free plastic or rubber material or a mixture of these materials.

According to the invention, the shield 4 consists of one or more prefabricated bands that are woven. The band comprises copper wire, optionally soot plated, or other suitable conductive material. The shield band 4 is provided in the longitudinal direction. In the following, however, it is assumed that only one band is used and good shielding is the main case. The shielding function is further enhanced when the edges or side edges of the bands overlap, ie when the bands form the overlap 8 shown in FIG.

In the case of the woven band shown in more detail in FIG. 4,
This band consists of longitudinally extending wires 6 which are held together by transverse connecting wires 7, said connecting wires optionally being made of a different material than the longitudinally extending wires 6. . In the woven shield band 4 shown in FIG. 1, all longitudinally extending wires 6 have the same diameter. Among other things, this has the advantage that the overlap is seen as shown in FIG. This is advantageous when making electrical contacts.

FIG. 2 illustrates the configuration of the shield band 4 provided on the electric cable in the embodiment of the present invention. In this configuration example, the periphery of the structure, that is, the cable portion 1 under the shield is covered. The longitudinally extending wire 6 has a diameter larger than the diameter of the longitudinally extending wire 6a that overlaps along the side edge of the shield band 4. The shield band 4 is also provided with a wire whose diameter decreases continuously towards the side edges. The advantage provided by this is that the cable diameter is smaller at the overlap and in particular the cable is smoother.

Figures 3a and 3b illustrate a combination of longitudinally extending wires of different diameters. Among other things, this combination offers the advantage that the overlap obtains a locking function, since a larger diameter wire extending longitudinally along one side edge of the band 4 causes the other side of the band 4 to This is because it "hooks" into the space between the smaller diameter wires that extend longitudinally along the edge. Said combination also offers the advantage of a smaller cable diameter in the overlap.

FIG. 5 shows a shield band 4 constructed according to the present invention.
A shield band which, due to its band structure, has the important advantage that an electrical connection or contact can easily be achieved by stripping the cable sheath and then twisting the cable bands together to form another conductor. Is illustrated. This is difficult and time consuming to achieve with a normally constructed braided shield,
This is because the braided shield must be sliced or cut open to form the conductor and then folded. Furthermore, there is a risk that the cable part will be damaged when the shield is cut open.

The shield structure has a dual function in the case of a coaxial cable. In this case, the shield band functions both as an electric conductor and as a shield. Here, the electric conductor means that the conductor wire and the shield band formed by the cable portion have substantially the same area, that is, the conductor has a sufficient area to ensure that the conductor function of the shield band is realized. Means that. The shielding capacity of the shield band is matched to the physical tightness of the band.

If greater demands are placed on the shielding capacity of the shield, or if a tighter wound shield or a tighter shield is desired, the shield structure can be supplemented by a metal foil. The metal foil is arranged between the cable part and the shield and / or between the shield and the cable sheath and can be composed of pure aluminum foil, aluminum coated plastic foil, pure copper foil, copper coated plastic foil or micro metal foil. is there.
It must be oriented with the metal side facing the shield band. When a metal foil is present between the cable portion and the shield band, the metal foil has the dual function of shielding the cable and providing solder protection when connecting the solder contacts to the shield.

The shield structure is sheathed or bundled to hold the shield band together. The sheath optionally comprises an insulating layer of halogen-free plastic or rubber material or a mixture of these materials. The binding is done with plastic bands or metal foils according to the above.

As mentioned above, the shield 4 comprises one or more prefabricated woven bands. In applications where a good shielding effect is mainly required, the shield band 4 is
It is formed so that its full width exceeds the perimeter of the underlying structure. The band 4 is formed according to any one of the structural examples in the overlap 8 described above with reference to FIGS. 2 and 3.

Some structural applications in which shield bands may be used are described below in connection with FIGS. 6 and 7. Sixth
The figure illustrates a structure that includes both an unshielded cable section 1a and an individually shielded cable section 1b. Figure 7 shows a twisted shielded section 1c and this shielded section 1c. 1 illustrates a structure that includes a further shield 9 located outside of the containing portion 1c.
It will be appreciated that these figures are to be seen merely as examples and other combinations are possible. The scope of use is individually shielded cable parts, shielded twisted pair cables, etc.

In all cases, the shield structure is the outer shield 9
Manufactured according to any one of the alternatives described above, including. To hold the shield bands together, they are bound together, such as by a plastic band 10. If high demands are made on the shielding capacity of the shield band, the retaining band 10 can consist of metal foil according to what has been described above.

Several practical effects are obtained when electrically connecting the aforementioned structures. In the case of a crimp connection, it is possible to easily insert a crimping sieve under the shield band 4 because of the fact that the overlapping parts of the shield band move apart naturally. Is. The individual connections of the shield band 4 can be made very easily. After stripping its sheath from the cable, the shield band can be easily separated from said cable section according to Fig. 5 without the use of a special tool (at the risk of damaging the cable section) and to the electrical contacts. Can be connected with. Since the shield can be easily formed on the conductor, the electrical contact structure can be correspondingly formed in a simple manner.

Another practical effect achieved by the present invention is illustrated in FIGS. As illustrated in FIG. 9, a portion of the sheath 5 is stripped off without damaging the shield band 4 and then the shield band is collected together to form the cable portion 1.
By forming a separate wire, the cable is equipped with a novel cable structure to provide an outlet
t), so-called T-joints can easily be formed. The shield band 4 and the cable section 1 are then inserted into separate "compartments" that are insulated from each other in one half of the T-joint 11, as illustrated in FIG. A fitting tag (not shown) inserted into the slot 12 connects the shield 4 as well as the cable portion 1 to the other half of the T-joint (which in this case is the cable as shown in the lower part of FIG. 8). It has the function of connecting to the corresponding shield and cable portions respectively, which are similarly configured) except that they come from only one direction.

Other practical process / technical advantages and advantages are achieved in the manufacture of the aforementioned shield structure. Bands are pre-made, so you can speed up production.
One manufacturing process is dispensed with, which makes it possible, for example, to produce a cable according to the one described above in a single manufacturing process.

It will be appreciated that the invention is not limited to the embodiments described and illustrated above, but that variations can be made within the scope of the following claims.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Niiberg, Agne, Hugo S-791 33 Falun, Freyabergen 27 (56) References JP-A-4-104407 (JP, A) JP-A-4-184998 (JP, a) JP flat 1-232611 (JP, a) JitsuHiraku flat 3-100322 (JP, U) JitsuHiraku Akira 56-146315 (JP, U) (58 ) investigated the field (Int.Cl. ⁷ , DB name) H01B 7/18-7/22 H01B 11/00-11/22

Claims (13)

(57) [Claims] 1. At least one cable portion, at least one shield surrounding the portion, and a plastic or rubber cable sheath surrounding the cable portion and the shield, each cable portion being a copper wire. Or a wire made of some other electrically conductive material,
An insulating layer of plastic or rubber, said shield (4) consisting of one or more woven and prefabricated shield bands, and enclosing said cable portion (1). Longitudinally arranged, the overall width of said shield band is greater than the perimeter of the underlying structure to form an overlap (8), and said shield band (4) is longitudinal An electrical cable having a wire (6) extending in a horizontal direction and a lateral retaining wire (7), the overlapping wire extending longitudinally along a side edge of the shield band having a smaller diameter than the remaining wires. An electric cable characterized by having. 2. At least one cable portion, at least one shield surrounding the portion, and a plastic or rubber cable sheath surrounding the cable portion and the shield, each cable portion being a copper wire. Or a wire made of some other electrically conductive material and an insulating layer of plastic or rubber, said shield (4) comprising one or more woven and prefabricated shield bands. And is arranged in the longitudinal direction around the cable portion (1),
The full width of the woven band (4) is greater than the perimeter of the underlying structure to form an overlap (8), and the shield band (4) is a longitudinally extending wire (4). 6) and a lateral retaining wire (7), the longitudinally extending wires (6) having different diameters to obtain a locking effect in the overlap (8). An electric cable characterized by having. 3. Electric cable according to claim 1 or 2, characterized in that the shield band (4) is made of copper wire or some other electrically conductive material. 4. The electric cable according to claim 1 or 2, characterized in that the total cross-sectional area of the shield band (4) is of the same size as the conductive area of the cable portion (1). And electrical cable. 5. The electric cable according to claim 1 or 2, characterized in that a metal foil is arranged between the shield band (4) and the cable portion (1). 6. The electric cable according to claim 1, wherein a metal foil is arranged between the cable sheath (5) and the shield band (4). 7. The electric cable according to claim 5, wherein the metal foil is made of aluminum, copper, plastic-coated aluminum or copper, or micro metal. 8. The electric cable according to claim 7, wherein
Electrical cable, characterized in that the metal side of the plastic-coated material faces the shield band (4). 9. An electrical cable according to claim 1 or 2, wherein the cable comprises several cable parts (1) and each said cable part or pair of cable parts is enclosed. An electric cable, characterized in that one or more shield bands (4) are arranged. 10. Electrical cable according to claim 1 or 2, characterized in that the cable comprises several cable parts (1), and that only one cable part is enclosed.
An electrical cable, characterized in that one or more shield bands (4) are arranged. 11. Electrical cable according to claim 9 or 10, wherein a further shield band (9) is provided outside the enclosure of the shielded and unshielded cable part (1). ) Is located inside the electrical cable. 12. The electric cable according to claim 11, wherein the further shield band (9) extends around the cable section (1).
An electric cable, which is configured in the same manner as the above. 13. The electrical cable according to claim 12, wherein a metal foil is provided between the further shield band (9) and the underlying structure, or the cable sheath (5) and the further shield band (9). ) An electric cable, characterized in that it is arranged between.